Source code that accompanies The CUDA Handbook.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

98 lines
3.1 KiB

/*
*
* nbody_CPU_SSE_openmp.cpp
*
* Multithreaded SSE CPU implementation of the O(N^2) N-body calculation.
* Uses SOA (structure of arrays) representation because it is a much
* better fit for SSE.
*
* Copyright (c) 2011-2012, Archaea Software, LLC.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifdef __SSE__
#ifdef _OPENMP
#include <xmmintrin.h>
#include <chTimer.h>
#include "nbody.h"
#include "bodybodyInteraction_SSE.h"
#include "nbody_CPU_SIMD.h"
float
ComputeGravitation_SIMD_openmp(
float *force[3],
float *pos[4],
float *mass,
float softeningSquared,
size_t N
)
{
chTimerTimestamp start, end;
chTimerGetTime( &start );
#pragma omp parallel for
for (int i = 0; i < N; i++)
{
__m128 ax = _mm_setzero_ps();
__m128 ay = _mm_setzero_ps();
__m128 az = _mm_setzero_ps();
__m128 *px = (__m128 *) pos[0];
__m128 *py = (__m128 *) pos[1];
__m128 *pz = (__m128 *) pos[2];
__m128 *pmass = (__m128 *) mass;
__m128 x0 = _mm_set_ps1( pos[0][i] );
__m128 y0 = _mm_set_ps1( pos[1][i] );
__m128 z0 = _mm_set_ps1( pos[2][i] );
for ( int j = 0; j < N/4; j++ ) {
bodyBodyInteraction(
ax, ay, az,
x0, y0, z0,
px[j], py[j], pz[j], pmass[j],
_mm_set_ps1( softeningSquared ) );
}
// Accumulate sum of four floats in the SSE register
ax = horizontal_sum_ps( ax );
ay = horizontal_sum_ps( ay );
az = horizontal_sum_ps( az );
_mm_store_ss( (float *) &force[0][i], ax );
_mm_store_ss( (float *) &force[1][i], ay );
_mm_store_ss( (float *) &force[2][i], az );
}
chTimerGetTime( &end );
return (float) chTimerElapsedTime( &start, &end ) * 1000.0f;
}
#endif
#endif